fix: prevent asset conflicts between React and Grid.js versions

Add coexistence checks to all enqueue methods to prevent loading
both React and Grid.js assets simultaneously.

Changes:
- ReactAdmin.php: Only enqueue React assets when ?react=1
- Init.php: Skip Grid.js when React active on admin pages
- Form.php, Coupon.php, Access.php: Restore classic assets when ?react=0
- Customer.php, Product.php, License.php: Add coexistence checks

Now the toggle between Classic and React versions works correctly.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

node_modules/@babel/runtime/helpers/regeneratorDefine.js

@@ -0,0 +1,22 @@
+function _regeneratorDefine(e, r, n, t) {
+  var i = Object.defineProperty;
+  try {
+    i({}, "", {});
+  } catch (e) {
+    i = 0;
+  }
+  module.exports = _regeneratorDefine = function regeneratorDefine(e, r, n, t) {
+    function o(r, n) {
+      _regeneratorDefine(e, r, function (e) {
+        return this._invoke(r, n, e);
+      });
+    }
+    r ? i ? i(e, r, {
+      value: n,
+      enumerable: !t,
+      configurable: !t,
+      writable: !t
+    }) : e[r] = n : (o("next", 0), o("throw", 1), o("return", 2));
+  }, module.exports.__esModule = true, module.exports["default"] = module.exports, _regeneratorDefine(e, r, n, t);
+}
+module.exports = _regeneratorDefine, module.exports.__esModule = true, module.exports["default"] = module.exports;